Signal transceiving apparatus and signal transceiving method

ABSTRACT

The present invention relates to a signal transceiving apparatus and a signal transceiving method. One embodiment of the present invention provides a signal transceiving method comprising: a step of generating HD video from UHD video and obtaining residual data of the UHD video, remaining after converting the HD video from the UHD video; and a step of transmitting the converted HD video to a base layer stream and the residual data to an enhancement layer stream.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Phase of PCT/KR2013/007154 filed onAug. 8, 2013, which claims priority under 35 U.S.C. 119(e) to U.S.Provisional Application No. 61/681,642 filed on Aug. 10, 2012, all ofwhich are hereby expressly incorporated by reference into the presentapplication.

TECHNICAL FIELD

The present invention relates to apparatuses for transmitting/receivingsignals and methods for transmitting/receiving signals.

BACKGROUND ART

As a video signal processing speed increases, methods forencoding/decoding ultra high definition (UHD) video signals are studied.UHD video is defined as a high definition (HD) video image having aresolution corresponding to quadruple or 16 times the resolution of HDvideo. High efficiency codec technology for transmitting UHD videotelevision signals using a single codec is developed by somestandardization organizations. However, current broadcast systems cannottransmit/receive UHD video even if a method for encoding/decoding theUHD video is provided since a method for transmitting the UHD video isnot defined in the current broadcast systems. Further, even when asystem for transmitting/receiving the UHD video is provided, the systemis less likely to be utilized unless the system is compatible withconventional video transmitting/receiving systems. Accordingly,compatibility with conventional broadcast or videotransmitting/receiving systems becomes an issue.

For example, when a conventional HDTV receiver receives UHD video, thereis no method for receiving or displaying HD video without any problems.Particularly, both UHDTV and HDTV need to receive or output videosignals without any problems using one UHD video in a process oftransmitting UHD signals. However, a method for receiving or outputtingvideo signals using one UHD has not been provided. Especially, a methodfor extracting 60 interlaced video frames from 60 progressive videoframes has not been proposed.

That is, there is no method for viewing HD compatible images without anyproblems when an HDTV receiver having a different scan mode and adifferent frame rate receives UHDTV streams.

DISCLOSURE Technical Problem

An object of the present invention is to provide methods fortransmitting/receiving signals and apparatuses fortransmitting/receiving signals, which are compatible with conventionalbroadcast or video transmitting/receiving systems when UHD video istransmitted and received.

Another object of the present invention is to provide methods fortransmitting/receiving signals and apparatuses fortransmitting/receiving signals to enable a conventional HDTV receiver toreceive or display HD video without any problems when receiving UHDvideo, in transmission and reception of the UHD video.

Technical Solution

To accomplish the object of the present invention, there is provided amethod for transmitting a signal, including: generating an HD video froma UHD video and acquiring residual data of the UHD video, remainingafter converting the HD video from the UHD video; and transmitting theconverted HD video as a base layer stream and transmitting the residualdata as an enhancement layer stream.

To accomplish the other object of the present invention, there isprovided an apparatus for receiving a signal, including: a receiver forreceiving an HD video and residual data for restoring a UHD video alongwith the HD video; and an output unit for decoding the HD video andoutputting the decoded HD video or restoring the UHD video using the HDvideo and the residual data and outputting the UHD video.

Advantageous Effects

According to embodiments of the present invention, it is possible toprovide a UHD video transmitting/receiving method compatible withconventional broadcast or video transmitting/receiving systems.

According to embodiments of the present invention, a conventional HDTVreceiver can receive or display HD video when receiving UHD video, intransmission and reception of UHD video.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a method for transmitting a signal according to anembodiment of the present invention.

FIG. 2 illustrates a method for generating a UHD video signal accordingto an embodiment of the present invention.

FIG. 3 illustrates the method shown in FIG. 2 in detail.

FIG. 4 illustrates another example of converting a UHD video signal intoan HD video signal.

FIG. 5 illustrates another example of converting a UHD video signal intoan HD video signal.

FIG. 6 illustrates another example of converting a UHD video signal intoa HD video signal in detail.

FIG. 7 illustrates another example of converting a UHD video signal intoan HD video signal in detail.

FIG. 8 illustrates an embodiment of a transmission apparatus capable oftransmitting a UHD video signal as an HD video signal.

FIG. 9 illustrates a video reception apparatus according to anembodiment of the present invention.

FIG. 10 illustrates an exemplary structure of a compatible broadcastsignal that can be received by both an HD broadcast receiver and a UHDbroadcast receiver.

FIG. 11 illustrates a PMT as signaling information.

FIG. 12 illustrates stream type values of streams according to anembodiment of the present invention.

FIG. 13 illustrates a UI-ID program descriptor according to anembodiment of the present invention.

FIG. 14 illustrates UHD_video_type field values and description thereof.

FIG. 15 illustrates UHD_sub_service_type field values and descriptionthereof.

FIG. 16 illustrates an example of UHD_enhancement_descriptor.

FIG. 17 illustrates a VCT as signaling information according to anembodiment of the present invention.

FIG. 18 illustrates a descriptor that can be included in the VCTaccording to an embodiment of the present invention.

FIG. 19 illustrates an SDT as signaling information.

FIG. 20 illustrates an EIT as signaling information.

FIG. 21 illustrates a method for receiving a broadcast signal accordingto an embodiment of the present invention.

FIG. 22 illustrates an apparatus for transmitting a signal according toan embodiment of the present invention.

FIG. 23 illustrates an apparatus for receiving a signal according to anembodiment of the present invention.

BEST MODE

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

FIG. 1 illustrates a method for transmitting a signal according to anembodiment of the present invention. The method for transmitting asignal according to an embodiment of the present invention will now bedescribed with reference to FIG. 1.

UHD video data is converted to HD video data (S110).

For example, when UHD video data is converted into HD video data, UHDvideo data of a first frame rate can be converted into progressive HDvideo data of the first frame rate, and the converted progressive HDvideo data of the first frame rate can be converted into progressive HDvideo data of a second frame rate corresponding to half the first framerate or into interlaced HD video data of the first frame rate.

Alternatively, in conversion of UHD video data into HD video data, a UHDvideo data of the first frame rate can be converted into progressive HDvideo data of the second frame rate corresponding to half the firstframe rate or into interlaced HD video data of the first frame rate.

An embodiment of converting UHD video data into HD video data isillustrated in FIG. 3. The embodiment shown in FIG. 3 is illustrated indetail in FIGS. 4 to 8.

The converted HD video data and residual data, which can be used todecode the UHD video data along with the HD video data, are transmitted(S120).

For example, signaling information for signaling a base layer stream andan enhancement layer stream can be generated and the base layer stream,the enhancement layer stream and the signaling information can bemultiplexed. This will be described below with reference to FIG. 8.

According to an embodiment of the present invention, an additionallytransmitted HD video and signaling information used to decode a UHDvideo using the HD video may be simultaneously transmitted. Thesignaling information will be described below in detail with referenceto FIGS. 10 to 20.

FIG. 2 illustrates a method for composing a UHD video signal accordingto an embodiment of the present invention.

The source of a UHD video may be encoded into a base layer and anenhancement layer using SVC. HD video signals may be extracted from thesource of the UHD video and encoded into a base layer, and a residualvideo signal necessary to upscale the HD video signals into UHD videosignals may be encoded into the enhancement layer.

In the present embodiment, the source of the UHD video is encoded into abase layer of 60 interleaved HD video data or 30 progressive HD videodata. In addition, upscaling may be performed (the 30 progressive HDvideo data are upscaled into 30 progressive UHD video data and the 60interlaced HD video data are upscaled into 60 interlaced UHD video data)and the residual video signal may be encoded into the enhancement layer.

FIG. 3 illustrates an example of the embodiment shown in FIG. 2 indetail. A description will be given of two examples of separating an HDvideo from a UHD video.

The first example includes a first step of converting 60 progressive UHDvideo data (3840×2160@60p) into 60 progressive HD video data(1920×1080@60p) and a second step of converting the extracted 60progressive HD video frames into HD videos corresponding to 60interlaced HD video data (1920×1080@60i) or 30 progressive HD video data(1920×1080@30p) in the case of 4K UHD video.

In this figure, the 60 progressive UHD video data are down-sampled into60 progressive HD video data using scaling, decimation or the like so asto extract the 60 progressive HD video data (UHD-to-HD down-sampling).In the present embodiment, the 60 progressive HD video data can beencoded into 60i HD video data using top/down field sampling or encodedinto 30p HD video data through frame sampling on an even or odd framebasis. The encoded 60i HD video data or 30p HD video data are encodedinto a base layer and transmitted.

In the second example, 60 progressive UHD video data (3840×2160@60p) canbe directly converted into HD videos corresponding to 60 interlaced HDvideo data (1920×1080@60i) or 30 progressive HD video data(1920×1080@30p) without the first step.

In the UHD videos, the HD video signals 1920×1080@60i can be extractedthrough down-sampling (scaling or decimation) and the HD video signals1920×1080@30p can be extracted through a method using frame skipping anddown-sampling.

In the two examples, UHD residual data corresponding to the differencebetween the UHD videos and the HD videos is encoded into an enhancementlayer and transmitted.

FIG. 4 illustrates the above-described example of converting UHD videointo HD video in detail. In the figure, a UHD video of 3840×2160@60p canbe converted into an HD video of 1920×1080@60p or 1920×1080@60i throughpixel sampling.

One of sampling methods for converting UHD video to HD video isdecimation that selects and converts only pixels of specific positionsthrough sampling. Four cases are possible according to samplingposition. That is, in four pixel regions, it is possible to use (1)sampling of combinations of even positions on the abscissa and evenpositions on the ordinate, (2) sampling of combinations of evenpositions on the abscissa and odd positions on the ordinate, (3)sampling of combinations of odd positions on the abscissa and evenpositions on the ordinate and (4) sampling of combinations of oddpositions on the abscissa and odd positions on the ordinate. The figureillustrates decimation that converts UHD video into HD video throughsimple sampling of (even, even) combination in the UI-ID video.1920×1080@60i HD video can be obtained by extracting HD interlaced videofrom the 1920×1080@60p HD video acquired as described above. While four2×2 pixel regions are selected in the case of 4K UHD video, 16 4×4 pixelregions may be used in the case of 8K UHD video.

FIG. 5 illustrates another example of converting UHD video into HD videoin detail. In the case of 4K UHD video, four samples in a 2×2 pixelregion of a video signal can be weighted and sampled, and an interlacedfield can be extracted from the sampled HD video. Here, a mathematicalexpression applied to each pixel is as illustrated in the figure and thesum of coefficients of respective pixels can be 1. That is, the 4K UHDvideo can be down-sampled such that a new HD pixel is formed for everyfour pixels. In another method for generating an HD video from a UHDvideo, the number of input pixels used in spatial down-sampling is notlimited to 2×2 in the above embodiment and N×N neighboring pixels can beused.

FIG. 6 illustrates another example of converting UHD video into HDvideo. This figure shows an example of directly converting UHD videodata (3840×2160@60p) into HD video data (1920×1080@60i).

For example, when the UHD video data (3840×2160@60p) are down-sampledinto the HD video data (1920×1080@60i), only odd frames or even framesare selected. In this example, odd frames (frame #1 and frame #3) areselected. When sub-sampling is performed, a pixel HD (x, y) of the oddtop field of an HD video frame can be determined using a pixel UHD (2x,2y) in the UHD video odd frame (frame #1), and a pixel UHD (2x, 4y+2) inthe same UHD video odd frame (frame #1) can be determined as a pixel HD(x, y+1) of the odd bottom field of the HD video frame. Since the sameframe (frame #1) is used, a UHD video frame can be converted into an HDvideo interlaced frame without having a time difference.

In the same manner, a pixel HD (x, y) of the odd top field of an HDvideo frame can be determined using a pixel UHD (2x, 2y) in the UHDvideo odd frame (frame #3), and a pixel UHD (2x, 4y+2) in the same UHDvideo odd frame (frame #3) can be determined as the pixel HD (x, y+1) ofthe odd bottom field of the HD video frame.

To generate 60 interlaced fields from 60 UHD source video data, a topfield and a bottom field are used in every odd (or even) frame. That is,the top field and the bottom field use the same frame, and a method ofgenerating 1 pixel, having a weight of 4 pixels, in a UHD video frame isapplied and sampling is performed while skipping 2 pixels each in thevertical direction.

In this manner, the UHD video data (3840×2160@60p) can be converted intothe HD video data (1920×1080@60i) and the converted frames can beencoded into a base layer and transmitted.

FIG. 7 illustrates another example of converting UHD video data into HDvideo data in detail. This figure shows another example of directlyconverting the video data (3840×2160@60p) into the HD video data(1920×1080@600.

For example, when the UHD video data (3840×2160@60p) are down-sampledinto the HD video data (1920×1080@60i), all frames are selected asdown-sampling targets. When sub-sampling is performed, a pixel HD (x, y)of the odd top field of an HD video frame can be determined using apixel UHD (2x, 2y) in the UHD video frame (frame #1), and a pixel UHD(2x, 4y+2) in the next UHD video frame (frame #2) can be determined as apixel HD (x, y+1) of the even bottom field of the HD video frame.Similarly, the odd top field and even bottom field of the HD video framecan be determined using UHD video frames #3 and #4.

While a top field can be generated in an odd frame and a bottom fieldcan be generated in an even frame in order to generate 60 interlacedfields from 60 UHD source video frames in this example, the bottom fieldmay be generated in an odd frame and the top field may be generated inan even frame. That is, a top field or a bottom field of an HD videoframe can be generated from every UHD video frame.

Accordingly, the UHD video data (3840×2160@60p) can be directlyconverted into the HD video data (1920×1080@60i) and the convertedframes can be encoded into a base layer and transmitted.

Method for separating an HD video frame from a UHD video frame mayinclude a method for sampling the UHD video frame to the HD video frameand then separating interlaced fields from the HD video frame, as shownin FIGS. 4 and 5. Further, the method may include a method for samplingthe UHD video frame to the HD video frame and, simultaneously,separating interlaced frames from the HD video frame, as shown in FIGS.6 and 7.

While a corresponding pixel of the HD video frame is generated using onepixel of the UHD video frame in FIGS. 6 and 7, HD video pixels may begenerated using the weighted sum of N arbitrary pixels. That is,down-sampling for extracting the HD video frame from the UHD video framecan be normalized and represented as Equation 1.

$\begin{matrix}{{{HD}( {x,y} )} = {\frac{1}{( {{N\; 1} + {N\; 2} + 1} )*( {{N\; 3} + {N\; 4} + 1} )}{\sum\limits_{i = {{- N}\; 1}}^{i = {{+ N}\; 2}}\;{\sum\limits_{j = {{- N}\; 2}}^{j = {{+ N}\; 4}}\;{{w( {i,j} )}*{{UD}( {{{2x} + i},{{2\; y} + j}} )}}}}}} & \lbrack {{Equation}\mspace{14mu} 1} \rbrack\end{matrix}$

FIG. 8 illustrates an embodiment of a transmission apparatus capable oftransmitting a UHD video signal as an HD video signal. When the UHDvideo signal, is input, the UHD video signal is selectively filteredthrough a low pass filter 110 and a sub-video sampling factor is inputto a down-sampling unit 120. This figure shows an example of classifyingHD video data according to scan methods when the sub-video samplingfactor is an (even, even) combination. Accordingly, other sub-videosampling factors can be used. The down-sampling unit 120 down-samplesthe filtered UHD video signal to an HD video signal. Down-samplingmethods are illustrated in FIGS. 3 and 4.

A format decision unit 130 may determine whether a video format isinterlaced or progressive according to scan method for the down-sampledvideo. The format decision unit 130 may generate 60i HD video frames byseparating top/bottom fields according to scan method and/or 30p HDvideo frames sampled on a frame basis and insert an interlaced flag anda progressive flag into the generated video frame.

In the case of the examples of FIGS. 6 and 7, the down-sampling unit 120and the format decision unit 130 can operate in the same functionalblock to simultaneously perform down-sampling and format conversionaccording to the above-described equation.

The video transmission apparatus according to an embodiment of thepresent invention may further include a signaling unit (not shown) forgenerating signaling information associated with the HD video signalconverted from the UHD video signal and a transmission unit (not shown)for simultaneously transmitting the converted HD video signal and thegenerated signaling information, when the HD video signal converted fromthe UHD video signal is transmitted as a broadcast signal.

A description will be given of a reception apparatus capable ofreceiving a video signal and signaling information.

FIG. 9 illustrates a video reception apparatus according to anembodiment of the present invention. The video reception apparatusaccording to the present invention can reproduce a UHD video and an HDvideo according to the aforementioned video structures.

A video reception apparatus according to a first embodiment of thepresent invention may include a demultiplexer 210, a video decoder 220 aand a video output unit 270. A video reception apparatus according to asecond embodiment of the present invention may include the demultiplexer210, video decoders 220 a and 220 b, an up-scaling unit 240, a videoconversion unit 250 and video output units 270 a and 270 b.

The video reception apparatuses according to the embodiments can receiveand reproduce HD video signals of a base layer and UHD video signals ofa base layer and an enhancement layer. The embodiments correspond to anexample of a UHD video receiver compatible with HD video signals.

The video reception apparatus for reproducing HD video signals of a baselayer according to the first embodiment will now be described first.Since the video reception apparatus according to the first embodimentcannot recognize an enhancement layer and recognizes only the HD videosignals of the base layer, the video reception apparatus receives onlyHD broadcast signals even when connected to a UHDTV broadcast channel.

The demultiplexer 210 demultiplexes a video stream of the base layer.The video stream of the base layer may have a format of 1920×1080@60i or1920×1080@30p. The video decoder 220 a may decode the demultiplexedvideo stream of the base layer and the video output unit 270 a mayoutput the decoded video stream of the base layer.

In the video reception apparatus according to the second embodiment, thedemultiplexer 210 may demultiplex and output the video stream. Theup-scaling unit 240 may up-scale the video stream in the format of1920×1080@60i or 1920×1080@30p, decoded by the video decoder 220 a.Up-scaling may conform to the methods illustrated in FIGS. 3 and 4.

The demultiplexer 210 may demultiplex a video stream of an enhancementlayer and the video decoder 220 b may decode UHD residual data of thedemultiplexed enhancement layer.

The video conversion unit 250 may generate UHD video data (e.g.3840×2160@60p) by summing the video data UHD-up-scaled by the up-scalingunit 240 and the UHD residual data decoded by the video decoder 220 b.

The present embodiment illustrates a case in which the HD video1920×1080@60i or 1920×1080@30p is reproduced as the UHD video3840×2160@60p. In the case of 8K UHD video (7680×4320), reproduction canbe performed in the same manner with a different up-scaling size. Thevideo output unit 270 b may output the UHD video summed by the videoconversion unit 250.

A signaling unit (not shown), which decodes signaling information forsignaling the aforementioned configuration, may be included in the videoreception apparatus. When the signaling information is transmitted as abroadcast stream or an additional stream, a receiver can recognize theconfiguration of a corresponding broadcast signal using the signalinginformation and decode the broadcast signal on the basis of theconfiguration thereof. A description will be given of the signalinginformation.

A configuration of a compatible broadcast signal which can be receivedby both an HD broadcast receiver and a UHD broadcast receiver will nowbe described.

FIG. 10 illustrates an exemplary configuration of a compatible broadcastsignal which can be received by both the HD broadcast receiver and theUHD broadcast receiver. A description will be given of an example of theconfiguration of a compatible broadcast signal which can be received byboth the HD broadcast receiver and the UHD broadcast receiver withreference to FIG. 10.

Program A may be referred to as service A or channel A and program B maybe referred to as service B or channel B.

Program A corresponding to an HD program and program B corresponding toa UHD program may be respectively transmitted as separate programs orseparate broadcast signals. For example, program A corresponding to theHD program and program B corresponding to the UHD program can berespectively transmitted as separate streams or separate broadcastsignals.

In this case, the HD broadcast receiver can receive HD program A and theUHD broadcast receiver can receive the UHD program B.

According to another embodiment, HD program A and the UHD program B arenot transmitted as separate programs and part of components of the UHDprogram may become components of the HD program. Examples of broadcastvideo components included in programs will now be described.

Program A may include an HD video component (component 1) and program Bmay include the HD video component (component 1) and an enhancementvideo component (component 2) for UHD video. Accordingly, the HD programcan correspond to part of the elements or components of the UHD program.

In this case, the UHD receiver can receive both HD video component 1 andenhancement video component 2 and reproduce a UHD video signal usingboth components.

Accordingly, the HD broadcast receiver receives HD video component 1 andthe UHD video receiver receives both HD video component 1 and UHD videocomponent 2.

Signaling information used for a broadcast receiver to receive anelement or a component will now be described.

FIG. 11 shows a PMT as the signaling information. An example ofsignaling a UHD video signal configuration will now be described withreference to FIG. 11

The PMT may conform to the contents disclosed in ISO/IEC 13818-1. Fieldsof the PMT will now be described using the contents of ISO/IEC 13818-1.

table_id field represents an 8-bit identifier that indicates the type ofthe PMT section. (table_id—This is an 8-bit field, which in the case ofa TS_program_map_section shall be always set to 0x02.)

section_syntax_indicator field is a 1-bit field set to 1 for a VCTsection. (section_syntax_indicator—The section_syntax_indicator is a1-bit field which shall be set to ‘1’.)

section_length field indicates the length of the corresponding section.(section_(—) length—This is a 12-bit field, the first two bits of whichshall be ‘00’. The remaining 10 bits specify the number of bytes of thesection starting immediately following the section_length field, andincluding the CRC.)

program_number field indicates a program to which program_map_PID isapplicable. (program_number—program_number is a 16-bit field. Itspecifies the program to which the program_map_PID is applicable. Oneprogram definition shall be carried within only oneTS_program_map_section. This implies that a program definition is neverlonger than 1016 (0x3F8). See Information Annex C for ways to deal withthe cases when that length is not sufficient. The program_number may beused as a designation for a broadcast channel, for example. Bydescribing the different program elements belonging to a program, datafrom different sources (e.g. sequential events) can be concatenatedtogether to form a continuous set of streams using a program_number.)

version_number field indicates the number of a VCT version.(version_number—This 5-bit field is the version number of theTS_program_map_section. The version number shall be incremented by 1modulo 32 when a change in the information carried within the sectionoccurs. Version number refers to the definition of a single program, andtherefore to a single section. When the current_next_indicator is set to‘1’, then the version_number shall be that of the currently applicableTS_program_map_section. When the current_next_indicator is set to ‘0’,then the version_number shall be that of the next applicableTS_program_map_section.)

current_next_indicator field indicates whether the PMT is applicablecurrently or next. (current_next_indicator—A 1-bit field, which when setto ‘1’ indicates that the TS_program_map_section sent is currentlyapplicable. When the bit is set to ‘0’, it indicates that theTS_program_map_section sent is not yet applicable and shall be the nextTS_program_map_section to become valid.)

section_number field indicates the number of the corresponding section.(section_number—The value of this 8-bit field shall be 0x00.)

last_section_number field indicates the number of the last section.(last_section_number—The value of this 8-bit field shall be 0x00.)

PCR_PID indicates the PID of a TS packet including a PCR field of aprogram specified by the program number. (PCR_PID—This is a 13-bit fieldindicating the PID of the Transport Stream packets which shall containthe PCR fields valid for the program specified by program_number. If noPCR is associated with a program definition for private streams, thenthis field shall take the value of 0x1FFF.)

program_info_length field indicates the length of a program leveldescriptor immediately following this field. (program_info_length—Thisis a 12-bit field, the first two bits of which shall be ‘00’. Theremaining 10 bits specify the number of bytes of the descriptorsimmediately following the program_info_length field.)

stream_type field indicates the type of a program element stream.(stream_type—This is an 8-bit field specifying the type of programelement carried within the packets with the PID whose value is specifiedby the elementary_PID.)

elementary_PID field designates the PID of a TS packet which carries anassociated program element. (elementary_PID—This is a 13-bit fieldspecifying the PID of the Transport Stream packets which carry theassociated program element.)

ES_info_length field indicates the length of a program element leveldescriptor. (ES_info_length—This is a 12-bit field, the first two bitsof which shall be ‘00’. The remaining 10 bits specify the number ofbytes of the descriptors of the associated program element immediatelyfollowing the ES_info_length field.)

CRC 32 field indicates a 32-bit field including a CRC value.(CRC_32—This is a 32-bit field that contains the CRC value that gives azero output of the registers in the decoder.)

The PMT may include a program level descriptor and an elementary streamlevel descriptor.

In the PMT, a descriptor that signals the UHD program and the HD programmay include a program level descriptor. In the present embodiment, theprogram descriptor is represented as UHD_program_descriptor.Characteristics of the UHD program can be signaled usingUHD_program_descriptor immediately following program_info_length fieldof the PMT.

The PMT may include an elementary stream level descriptor for signalingelements or components of the UHD program or the HD program. In thepresent embodiment, the elementary stream level descriptor isrepresented as UHD_enhancement_descriptor. Characteristics of elementarystreams or components can be signaled using the elementary stream leveldescriptor immediately following ES_info_length field.

The two descriptors will now be described in detail.

In the case of program B in FIG. 10, two video components can besignaled through the PMT. For example, component 1 which is an HD videocomponent can be signaled as a stream type such as MPEG-2, H.264/AVC,HEVC or the like. An enhancement video component can be signaled as astream type value that indicates the enhancement video component asstream_type.

The enhancement video component can designate a compression codec forcomponent 2. For example, the enhancement video component can be astream type value that indicates an AVC/SVC stream, an HEVC scalableextension stream, a stream acquired by coding a hybrid delta streamthrough AVC and a stream acquired by coding the hybrid delta streamusing HEVC.

Here, hybrid delta refers to a case in which a codec, which is differentfrom a codec used to compress a base layer video signal (component 1),is used for enhancement video data with respect to the base layer videosignal (component 1). That is, when component 1 with respect to an HDsignal is encoded according to MPEG-2 video and component 2 with respectto an enhancement layer for UHD video is encoded through HEVC, thecomponent 2 is called a hybrid delta HEVC stream.

When component 2 is encoded or decoded using hybrid delta, an encoder ora decoder can encode or decode component 2 using a result ofcomponent 1. If a base layer signal is an MPEG-2 video stream and anenhancement layer signal is a stream coded through HEVC, the base layersignal can be decompressed and then up-scaled according to a UHD signal.In addition, the enhancement layer signal compressed through HEVC can bedecompressed and then combined with the up-scaled MPEG-2 video signal tofinally output a UHD video signal.

FIG. 12 illustrates stream type values of streams according to anembodiment of the present invention. For example, a stream using anAVC/SVC codec can have a stream type value of 0x30.

FIG. 13 illustrates a UHD program descriptor according to an embodimentof the present invention. An exemplary UHD program descriptor will nowbe described with reference to FIG. 13. The UHD program descriptor mayindicate that the corresponding program is a UHD program and includeinformation on transmission structures of two layers (base layer andenhancement layer). The UHD program descriptor may immediately followprogram_info_length of the PMT.

The UHD program descriptor can include descriptor_tag field which is adescriptor identifier and a descriptor_length field which indicates thelength of the descriptor.

UHD_video_type field signals information on a UHD video format andindicates information representing whether the video type is 4K or 8K.This will be described below in detail with reference to FIG. 14.

UHD_sub_service_type field indicates information on compatibility of aUHD service with HD and a UHD service transmission structure. This willbe described below in detail with reference to FIG. 15.

FIG. 14 illustrates values of the aforementioned UHD_video_type fieldand description thereof. FIG. 14 shows values of UHD_video_type fieldand video formats according to the respective values. For example, whenUHD_video_type field is 001, UHD_video_type field indicates videoresolution of 3840×2160 and 60 progressive HD video frame(3840×2160@60p) per unit time.

FIG. 15 illustrates values of the aforementioned UHD_sub_service_typefield and description thereof. For example, when UHD_sub_service_typefield is 0x01, this value indicates that the UHD service is notcompatible with HD video. In the case of hybrid delivery, video streamsconstituting a UHD service are transmitted through a differenttransmission path or protocol. For example, a base layer is transmittedin-band and an enhancement layer is received through a differentpath/protocol such as the Internet in real-time, Internet download,in-band non-real-time or the like.

FIG. 16 illustrates an example of the aforementionedUHD_enhancement_descriptor. The UHD enhancement descriptor can signalinformation on an elementary stream corresponding to an enhancementlayer and immediately follows ES_info_length field of the PMT.

UHD_enhancement_descriptor can include descriptor_tag which is adescriptor identifier and a descriptor_length field which indicates thelength of the descriptor.

UHD_enhancement_descriptor can include UHD_video_type field whichindicates information on a UHD video format and anupscale_parameter_included field which indicates an upscaling parameter.

For example, UHD_video_type field signals information on a UHD videoformat and indicates information representing whether video is 4K or 8K.UHD_video_type field may have the same values as shown in FIG. 14.

Upscale_parameter_included field indicates whether an upscale parameter,which needs to be applied to the base layer prior to combination of thebase layer with the enhancement layer, is included in an enhancementlayer video stream. The decoder can perform upscaling on the base layerat UHD level using the upscale parameter.

FIG. 17 illustrates a VCT as signaling information according to anembodiment of the present invention. An example of signaling a UHD videosignal configuration will now be described with reference to FIG. 17.

The VCT can conform to ATSC PSIP. According to ATSC PSIP, fields of theVCT are as follows. Each bit will now be described.

table_id field indicates an 8-bit unsigned integer that refers to thetype of the corresponding table section. (table_id—An 8-bit unsignedinteger number that indicates the type of table section being definedhere. For the terrestrial_virtual_channeltable_section( ) the table_idshall be 0xC8.)

section_syntax_indicator field is a 1-bit field set to 1 for the VCTsection. (section_syntax_indicator—The section_syntax_indicator is aone-bit field which shall be set to ‘1’ for theterrestrial_virtual_channel_table_section ( ).)

private_indicator field is set to 1. (private_indicator—This 1-bit fieldshall be set to ‘1’).

section_length field indicates a section length in bytes.(section_length—This is a twelve bit field, the first two bits of whichshall be ‘00’. If specifies the number of bytes of the section, startingimmediately following the section_length field, and including the CRC.)

transport_stream_id field indicates an MPEG-TS ID as in the PAT that canidentify TVCT. (transport_stream_id—The 16-bit MPEG-2 Transport StreamID, as it appears in the Program Association Table (PAT) identified by aPID value of zero for this multiplex. The transport_stream_iddistinguishes this Terrestrial Virtual Channel Table from others thatmay be broadcast in different PTCs.)

version_number field indicates the version number of the VCT.(version_number—This 5-bit field is the version number of the VirtualChannel Table. For the current VCT (current_next_indicator=‘1’), theversion number shall be incremented by 1 whenever the definition of thecurrent VCT changes. Upon reaching the value 31, it wraps around to 0.For the next VCT (current_next_indicator=‘0’), the version number shallbe one unit more than that of the current VCT (also in modulo 32arithmetic). In any case, the value of the version_number shall beidentical to that of the corresponding entries in the MGT.)

current_next_indicator field indicates whether the VCT is applicablecurrently or next. (current_next_indicator—A one-bit indicator, whichwhen set to ‘1’ indicates that the Virtual Channel Table sent iscurrently applicable. When the bit is set to ‘0’, it indicates that thetable sent is not yet applicable and shall be the next table to becomevalid. This standard imposes no requirement that “next” tables (thosewith current_next_indicator set to ‘0’) must be sent. An update to thecurrently applicable table shall be signaled by incrementing theversion_number field.)

section_number field indicates the number of the corresponding section.(section_number—This 8-bit field gives the number of this section. Thesection_number of the first section in the Terrestrial Virtual ChannelTable shall be 0x00. It shall be incremented by one with each additionalsection in the Terrestrial Virtual Channel Table.)

last_section_number field indicates the number of the last section.(last_section_number—This 8-bit field specifies the number of the lastsection (that is, the section with the highest section_number) of thecomplete Terrestrial Virtual Channel Table.)

protocol_version field indicates a protocol version for parameters thatwill be structured differently than those defined in the currentprotocol. (protocol_version—An 8-bit unsigned integer field whosefunction is to allow, in the future, this table type to carry parametersthat may be structured differently than those defined in the currentprotocol. At present, the only valid value for protocol_version is zero.Non-zero values of protocol_version may be used by a future version ofthis standard to indicate structurally different tables.)

num_channels_in_section field indicates the number of virtual channelsof the VCT. (num_channels_in_section—This 8-bit field specifies thenumber of virtual channels in this VCT section. The number is limited bythe section length.)

short_name field indicates the name of a virtual channel.(short_name—The name of the virtual channel, represented as a sequenceof one to seven 16-bit code values interpreted in accordance with theUTF-16 representation of Unicode character data. If the length of thename requires fewer than seven 16-bit code values, this field shall bepadded out to seven 16-bit code values using the Unicode NUL character(0x0000). Unicode character data shall conform to The Unicode Standard,Version 3.0 [13].)

major_channel_number field indicates the number of major channelsassociated with the virtual channels. (major_channel_number—A 10-bitnumber that represents the “major” channel number associated with thevirtual channel being defined in this iteration of the “for” loop. Eachvirtual channel shall be associated with a major and a minor channelnumber. The major channel number, along with the minor channel number,act as the user's reference number for the virtual channel. Themajor_channel_number shall be between 1 and 99. The value ofmajor_channel_number shall be set such that in no case is amajor_channel_number/minor_channel_number pair duplicated within theTVCT. For major_channel_number assignments in the U.S., refer to AnnexB.)

minor_channel_number field indicates the number of minor channelsassociated with the virtual channels. (minor_channel_number—A 10-bitnumber in the range 0 to 999 that represents the “minor” or“sub”-channel number. This field, together with major_channel_number,performs as a two-part channel number, where minor_channel_numberrepresents the second or right-hand part of the number. When theservice_type is analog television, minor_channel_number shall be set to0. Services whose service_type is ATSC_digital television,ATSC_audio_only, or unassociated/small screen service shall use minornumbers between 1 and 99. The value of minor_channel_number shall be setsuch that in no case is a major_channel_number/minor_channel_number pairduplicated within the TVCT. For other types of services, such as databroadcasting, valid minor virtual channel numbers area between 1 and999.)

modulation_mode field indicates a modulation mode of carriers associatedwith the virtual channels. (modulation_mode—An 8-bit unsigned integernumber that indicates the modulation mode for the transmitted carrierassociated with this virtual channel. Values of modulation_mode shall beas defined in Table 6.5. For digital signals, the standard values formodulation mode (values below 0x80) indicate transport framingstructure, channel coding, interleaving, channel modulation, forwarderror correction, symbol rate, and other transmission-relatedparameters, by means of a reference to an appropriate standard. Themodulation_mode field shall be disregarded for inactive channels.)

carrier_frequency field is a field capable of identifying a carrierfrequency. (carrier_frequency—The recommended value for these 32 bits iszero. Use of this field to identify carrier frequency is allowed, but isdeprecated.)

channel_TSID field indicates an MPEG-2 TS ID associated with a TScarrying the MPEG-2 program referenced by this virtual channel.(channel_TSID—A 16-bit unsigned integer field in the range 0x0000 to0xFFFF that represents the MPEG-2 Transport Stream ID associated withthe Transport Stream carrying the MPEG-2 program referenced by thisvirtual channel. For inactive channels, channel_TSID shall represent theID of the Transport Stream that will carry the service when it becomesactive. The receiver is expected to use the channel_TSID to verify thatany received Transport Stream is actually the desired multiplex. Foranalog channels (service_type 0x0), channel_TSID shall indicate thevalue of the analog TSID included in the VBI of the NTSC signal. Referto Annex D section 9 for a discussion on use of the analog TSID.)

program_number field indicates an integer value defined with respect tothe corresponding virtual channel and the PMT. (program_number—A 16-bitunsigned inter number that associates the virtual channel being definedhere with the MPEG-2 PROGRAM ASSOCIATION and TS PRGRAM MAP tables. Forvirtual channels representing analog services, a value of 0xFFFF shallbe specified for program_number. For inactive channels (those notcurrently present in the Transport Stream), program_number shall be setto zero. This number shall not be interpreted as pointing to a ProgramMap Table entry.)

ETM_location field indicates presence and location of an ETM.(ETM_location—This 2-bit field specifies the existence and the locationof an Extended Text Message (ETM) and shall be as defined in Table 6.6.)

access_controlled field indicates an event associated with anaccess-controlled virtual channel. (access_controlled—A 1-bit Booleanflag that indicates, when set, that the events associated with thisvirtual channel may be access_controlled. When the flag is set to ‘0’,event access is not restricted.)

hidden field indicates a case in which the virtual channel is notaccessed by a direct channel input of the user. (hidden—a 1-bit Booleanflag that indicates, when set, that the virtual channel is not accessedby the user by direct entry of the virtual channel number. Hiddenvirtual channels are skipped when the user is channel surfing, andappear as if undefined, if accessed by direct channel entry. Typicalapplications for hidden channels are test signals and NVOD services.Whether a hidden channel and its events may appear in EPG displaysdepends on the state of the hide_guide bit.)

hide_guide channel indicates whether the virtual channel and the eventthereof can appear in an EPG. (hide_guide—A Boolean flag that indicates,when set to ‘0’ for a hidden channel, that the virtual channel and itsevents may appear in EPG display. This bit shall be ignored for channelswhich do not have the hidden bit set, so that non-hidden channels andtheir events may always be included in EPG displays regardless of thestate of the hide_guide bit. Typical applications for hidden channelswith the hide_guide bit set to ‘1’ are test signals and servicesaccessible through application-level pointers.)

service_type field indicates a service type identifier.(service_type—This 6-bit field shall carry the Service Type identifier.Service Type and the associated service_type field are defined in A/53Part 1 [1] to identify the type of service carried in this virtualchannel. Value 0x00 shall be reserved. Value 0x01 shall represent analogtelevision programming. Other values are defined in A/53 Part 3 [3], andother ATSC Standard may define other Service Types9.)

source_id field is a number that identifies the programming sourceassociated with the virtual channel. (source_id—A 16-bit unsignedinteger number that identifies the programming source associated withthe virtual channel. In this context, a source is one specific source ofvideo, text, data, or audio programming. Source ID value zero isreserved. Source ID values in the range 0x0001 to 0x0FFF shall be uniquewithin the Transport Stream that carries the VCT, while values 0x1000 to0xFFFF shall be unique at the regional level. Values for source ids0x1000 and above shall be issued and administered by a RegistrationAuthority designated by the ATSC.)

descriptor_length field indicates the length of the followingdescriptor. (descriptor_length—Total length (in bytes) of thedescriptors for this virtual channel that follows.)

The descriptor can be included in descriptor( ).

Descriptor( )—Zero or more descriptors, as appropriate, may be included.

additional-descriptors_length—Total length (in bytes) of the VCTdescriptor list that follows.

CRC 32 is a 32-bit field including a CRC value. (CRC_32—This is a 32-bitfield that contains the CRC value that ensures a zero output from theregisters in the decoder.)

The VCT can include service_type that indicates services associated withUHD broadcast and a descriptor that describes the services associatedwith UHD broadcast. For example, service_type field can have a fieldvalue (e.g. 0x07) indicating a parameterized service, a field value(e.g. 0x09) indicating an extended parameterized service or a fieldvalue (e.g. 0x10) indicating a new DTV service.

A descriptor that describes a UHD program and components thereof can belocated following descriptor_length.

FIG. 18 illustrates a descriptor that can be included in the VCTaccording to an embodiment of the present invention. A description willbe given of the descriptor that can be included in the VCT withreference to FIG. 18. In this example, the descriptor that can beincluded in the VCT is referred to as UHD_component_descriptor.

UHD_component_descriptor can include descriptor_tag that is theidentifier of the descriptor and descriptor_length field that indicatesthe length of the descriptor.

Num_of_component indicates the number of components included in thecorresponding UHD service.

UHD_(—) component_(—) descriptor may include UHD_video_codec_type,UHD_(—) video_(—) profile, UHD_video_resolution, UHD_video_frame_rateand UHD_component_type fields per component.

UHD_video_codec_type field indicates a codec for video elementsconstituting the UHD service. For example, this value can indicate thesame codec as that indicated by stream_type of the PMT.

UHD_video_profile field indicates a profile for a corresponding videostream, that is, a basic tool necessary to decode the correspondingvideo stream. UHD_video_profile can indicate requirement informationabout a color depth (4:2:0, 4:2:2), bit depth (8-bit, 10-bit), codingtool and the like of the corresponding video stream. UHD_video_levelindicates maximum specifications that can be decoded in thecorresponding profile. That is, UHD_video_profile field can providelevel information corresponding to UHD_video_resolution field andUHD_video_frame_rate.

UHD_video_resolution field and UHD_video_frame_rate field indicate aframe rate and resolution of UHD video. For example, whenUHD_video_resolution is ‘001’, this value can indicate resolution of3840×2160. When UHD_video_frame_rate is ‘010’, this value can indicateprogressive 60 Hz. UHD_video_resolution field and UHD_video_frame_ratefield can have the same meaning and values as those of UHD_video_typefield of UHD_program_descriptor included in the aforementioned PMT.

UHD_component_type field can indicate information representing whetherthe corresponding video stream is an HD compatible base layer or anenhancement layer for UHD.

A description will be given of an example of signaling a UHD videocompatible with an HD video using the aforementioned information throughDVB SI.

FIG. 19 illustrates an SDT as signaling information.

The SDT can conform to ETSI EN 300 468. Respective fields of the SDTwill now be described using ETSI EN 300 468.

table_id field indicates the identifier of the table.

section_syntax_indicator field is a 1-bit field set to 1 for the SDTsection. (section_syntax_indicator: This section_syntax_indicator is a1-bit field which shall be set to “1”.)

section_length field indicates the length of the section in bytes.(section_length: This is a 12-bit field, the first two bits of whichshall be “00”. It specifies the number of bytes of the section, startingimmediately following the section_length field and including the CRC.The section_length shall not exceed 1021 so that the entire section hasa maximum length of 1024 bytes.)

transport_(—) stream_id field indicates a TS identifier provided by theSDT, distinguished from any other multiplex in the transmission system.(transport_stream_id: This is a 16-bit field which serves as a label foridentification of the TS, about which the SDT informs, from any othermultiplex within the delivery system.)

version_number field indicates the version number of the sub-table.(version_number: This 5-bit field is the version number of thesub_table. The version_number shall be incremented by 1 when a change inthe information carried within the sub_table occurs. When it reachesvalue “31”, it wraps around to “0”. When the current_next_indicator isset to “1”, then the version_number shall be that of the currentlyapplicable sub_table. When the current_next_indicator is set to “0”,then the version_number shall be that of the next applicable sub_table.)

current_next_indicator field indicates whether the sub-table isapplicable currently or next. (current_next_indicator: This 1-bitindicator, when set to “1” indicates that the sub_table is the currentlyapplicable sub_table. When the bit is set to “0”, it indicates that thesub_table sent is not yet applicable and shall be the next sub_table tobe valid.)

section_number field indicates the number of the corresponding section.(section_number: This 8-bit field gives the number of the section. Thesection_number of the first section in the sub_table shall be “0x00”.The section_number shall be incremented by 1 with each additionalsection with the same table_id, transport_stream, andoriginal_network_id.)

last_section_number field indicates the number of the last section.(last_section_number: This 8-bit field specifies the number of the lastsection (that is, the section with the highest section_number) of thesub_table of which this section is part.)

original_network_id field identifies the network ID of the transmissionsystem. (original_network_id: This 16-bit field gives the labelidentifying the network_id of the originating delivery system.)

service_id field indicates a service identifier in the corresponding TS.(service_id: This is a 16-bit field which serves as a label to identifythis service from any other service within the TS. The service_id is thesame as the program_number in the corresponding program_map_section.)

EIT_schedule_flag field indicates whether EIT schedule information abouta corresponding service is present in the current TS.(EIT_schedule_flag: This is a 1-bit field which when set to “1”indicates that EIT schedule information for the service is present inthe current TS, see TR 101 211 [i.2] for information on maximum timeinterval between occurrences of an EIT schedule sub_table. If the flagis set to 0 then the EIT schedule information for the service should notbe present in the TS.)

EIT_present_following_flag field indicates whether EIT_present_followinginformation about the service is present in the current TS.(EIT_present_following_flag: This is a 1-bit field which when set to “1”indicates that EIT_present_following information for the service ispresent in the current TS, see TR 101 211 [i.2] for information onmaximum time interval between occurrences of an BIT present/followingsub_table. If the flag is set to 0 then the EIT present/followinginformation for the service should not be present in the TS.)

running_status field indicates the status of the service as defined intable 6 of DVB-SI. (running_status: This is a 3-bit field indicating thestatus of the service as defined in table 6. For an NVOD referenceservice the value of the running_status shall be set to “0”.)

free_CA_mode field indicates whether all component streams of theservice are scrambled. (free_CA_mode: This 1-bit field, when set to “1”indicates that all the component streams of the service are notscrambled. When set to “1” it indicates that access to one or morestreams may be controlled by a CA system.)

descriptors_loop_length field indicates the length of the followingdescriptor. (descriptors_loop_length: This 12-bit field gives the totallength in bytes of the following descriptors.)

CRC_32 is a 32-bit field including a CRC value.(descriptors_loop_length: This 12-bit field gives the total length inbytes of the following descriptors.)

UHD_program_descriptor illustrated in FIG. 13 can be located at theservice level of the SDT to signal UHD video characteristics andtransmission structure with respect to the corresponding service. Inaddition, UHD_component_descriptor illustrated in FIG. 18 can be locatedat the service level of the SDT to signal characteristics of UHDelements included in the corresponding service.

FIG. 20 illustrates an EIT as signaling information.

The EIT can conform to ETSI EN 300 468. Respective fields of the EITwill now be described using ETSI EN 300 468.

table_id field indicates a table identifier.

section_syntax_indicator field is a 1-bit field set to 1 for the EITsection. (section_syntax_indicator: The section_syntax_indicator is a1-bit field which shall be set to “1”.)

section_length field indicates the length of the section in bytes.(section_length: This is a 12-bit field. It specifies the number ofbytes of the section, starting immediately following the section_lengthfield and including the CRC. The section_length shall not exceed 4093 sothat the entire section has a maximum length of 4096 bytes.)

service_id field indicates a service identifier in a TS. (service_id:This is a 16-bit field which serves as a label to identify this servicefrom any other service within a TS. The service_id is the same as theprogram_number in the corresponding program_map_section.)

version_number field indicates the version number of the sub-table.(version_number: This 5-bit field is the version number of thesub_table. The version_number shall be incremented by 1 when a change inthe information carried within the sub_table occurs. When it reachesvalue 31, it wraps around to 0. When the current_next_indicator is setto “1”, then the version_number shall be that of the currentlyapplicable sub_table. When the current_next_indicator is set to “0”,then the version_number shall be that of the next applicable sub_table.)

current_next_indicator field indicates whether the sub-table isapplicable currently or next. (current_next_indicator: This 1-bitindicator, when set to “1” indicates that the sub_table is the currentlyapplicable sub_table. When the bit is set to “0”, it indicates that thesub_table sent is not yet applicable and shall be the next sub_table tobe valid.)

section_number field indicates the number of the section.(section_number: This 8-bit field gives the number of the section. Thesection_number of the first section in the sub_table shall be “0x00”.The section_number shall be incremented by 1 with each additionalsection with the same table_id, service_id, transport_stream_id, andoriginal_network_id. In this case, the sub_table may be structured as anumber of segments. Within each segment the section_number shallincrement by 1 with each additional section, but a gap in numbering ispermitted between the last section of a segment and the first section ofthe adjacent segment.)

last_section_number field indicates the number of the last section.(last_section_number: This 8-bit field specifies the number of the lastsection (that is, the section with the highest section_number) of thesub_table of which this section is part.)

transport_stream_id field indicates a TS identifier provided by the SDT,distinguished from any other multiplex within the transmission system.(transport_stream_id: This is a 16-bit field which serves as a label foridentification of the TS, about which the EIT informs, from any othermultiplex within the delivery system.)

original_network_id field identifies the network ID of the transmissionsystem. (original_network_id: This 16-bit field gives the labelidentifying the network_id of the originating delivery system.)

segment_last_section_number field indicates the number of the lastsection of this segment of the sub-table. (segment_last_section_number:This 8-bit field specifies the number of the last section of thissegment of the sub_table. For sub_tables which are not segmented, thisfield shall be set to the same value as the last_section_number field.)

last_table_id field is an 8-bit field that identifies the last table IDused (see table 2). (last_table_id: This 8-bit field identifies thelast_table_id used (see table 2).)

event_id field indicates the identification number of the describedevent. (event_id: This 16-bit field contains the identification numberof the described event (uniquely allocated within a service definition.)

start_time field includes the start time of the event. (start_time: This40-bit field contains the start time of the event in Universal Time,Co-ordinated (UTC) and Modified Julian Date (MJD) (see Annex C). Thisfield is coded as 16 bits giving the 16 LSBs of MJD followed by 24 bitscoded as 6 digits in 4-bit Binary Coded Decimal (BCD). If the start timeis undefined (e.g. for an event in a NVOD reference service) all bits ofthe field are set to “1”.)

running_status field indicates the status of the event as defined intable 6 of DVB SI. (running_status: This is a 3-bit field indicating thestatus of the event as defined in table 6. For an NVOD reference eventthe value of the running_status shall be set to “0”.)

free_CA_mode field indicates whether all component streams of theservice are scrambled. (free_CA_mode: This 1-bit field, when set to “0”indicates that all the component streams of the event are not scrambled.When set to “1” it indicates that access to one or more streams iscontrolled by a CA system.)

descriptors_loop_length field indicates the length of the followingdescriptor. (descriptors_loop_length: This is 12-bit field gives thetotal length in bytes of the following descriptors.)

CRC_32 is a 32-bit field including a CRC value. (CRC_32: This is a32-bit field that contains the CRC value that gives a zero output of theregisters in the decoder.)

UHD_program_descriptor illustrated in FIG. 13 andUHD_component_descriptor illustrated in FIG. 18 can be located at theevent level of the EIT to signal UHD video characteristics andtransmission structure with respect to the UHD program andcharacteristics of UHD elements included in the UHD service per event.

When UHD_component_descriptor illustrated in FIG. 18 is included in theSDT or EIT of DVB, UHD_component_descriptor may further include acomponent_tag field. The component_tag field can indicate a PID valuefor the corresponding stream signaled through the PMT at the PSI level.The receiver can detect the PID value of the corresponding stream alongwith the PMT using the component_tag field.

FIG. 21 illustrates a method for receiving a broadcast signal accordingto an embodiment of the present invention. An embodiment of the methodfor receiving a broadcast signal according to the present invention willnow be described.

HD video data is received, and residual data that can restore UHD videodata along with the HD video data is received (S210).

The HD video data is decoded and output or the UHD video data isrestored using the HD video data and the residual data and output(S220). S210 and S220 have been described in detail with reference toFIG. 9.

According to the method for receiving a broadcast signal according to anembodiment of the present invention, signaling information may bereceived and S220 may be performed using the signaling information. Thesignaling information has been described with reference to FIGS. 10 to20.

When the HD video data, the residual data used to restore the UHD videodata along with the HD video data, and the signaling information aremultiplexed and transmitted, an HD video stream, a residual data streamand the signaling information can be respectively demultiplexed.

The demultiplexed signaling information can be decoded and thedemultiplexed HD video stream can be restored according to the decodedsignaling information or the UHD video signal can be restored using thedemultiplexed HD video stream and residual data stream.

FIG. 22 illustrates an apparatus for transmitting a signal according toan embodiment of the present invention.

The apparatus for transmitting a signal according to an embodiment ofthe present invention may include a converter 310 and a transmitter 340.

The converter 310 converts UHD video data into HD video data.

For example, when UHD video data is converted into HD video data, theconverter 310 can convert UHD video data of a first frame rate intoprogressive HD video data of the first frame rate and convert theconverted first frame rate progressive HD video data into progressive HDvideo data of a second frame rate corresponding to half the first framerate or into interlaced HD video data of the first frame rate.

In conversion of UHD video data into HD video data, the converter 310may convert UHD video data of a first frame rate into progressive HDvideo data of a second frame rate corresponding to half the first framerate or into interlaced HD video data of the first frame rate.

An embodiment of converting the UHD video data into the HD video datahas been described with reference to FIG. 3. The embodiment illustratedin FIG. 3 has been described in detail with reference to FIGS. 4 to 8.

The transmitter 340 transmits the HD video data converted by theconverter 310 and the residual data used to restore the UHD video dataalong with the converted HD video data.

The apparatus for transmitting a signal according to an embodiment ofthe present invention may further include a signaling unit 320 and amultiplexer 330. The signaling unit 320 generates signaling informationused to restore the UHD video data using the transmitted HD video dataand residual data of the HD video data. The signaling information hasbeen described in detail with reference to FIGS. 10 to 20.

The multiplexer 330 multiplexes the HD video data converted by theconverter 310, the residual data and the signaling information generatedby the signaling unit 330.

The transmitter 340 can transmit the signal multiplexed by themultiplexer 330.

FIG. 23 illustrates an apparatus for receiving a signal according to anembodiment of the present invention.

The apparatus for receiving a signal according to an embodiment of thepresent invention may include a receiver 410, a decoder 440 and anoutput unit 450.

The receiver 410 receives HD video data and residual data used torestore corresponding UHD video data along with the residual data.

The decoder 440 may decode the HD video data or decode the UHD videodata using the HD video data and the residual data.

The output unit 450 may decode the HD video data or restore the UHDvideo data using the HD video data and the residual data. The decoder440 and the output unit 450 have been described in detail with referenceto FIG. 9.

The apparatus for receiving a signal according to an embodiment of thepresent invention may further include a demultiplexer 420 and asignaling information decoder 430.

When the HD video data, residual data used to restore the UHD video dataalong with the HD video data and signaling information are multiplexedand transmitted, the demultiplexer 420 may demultiplex an HD videostream, a residual data stream and the signaling information.

The signaling information decoder 440 may decode the demultiplexedsignaling information.

Then, the decoder 440 can decode the HD video data demultiplexed by thedemultiplexer 420 according to the decoded signaling information orrestore the UHD video data using the demultiplexed HD video stream andresidual data stream.

MODE FOR INVENTION

The best mode for the invention has been described.

INDUSTRIAL APPLICABILITY

The present invention can be used in broadcast and video signalprocessing fields, has reproducibility and is industrially applicable.

The invention claimed is:
 1. A method for transmitting a broadcastsignal, the method comprising: generating high definition (HD) videodata from ultra high definition (UHD) video data; wherein the UHD videodata is converted to the HD video data by: filtering the UHD video datathrough a low pass filter, down-sampling the filtered UHD video datausing a sub-video sampling factor which is a combination of even or oddpixels in a sampling unit, and generating, based on the down-sampled UHDvideo data, the HD video data in an interlaced way in which thegenerated HD video data includes interlaced HD video frames by scanningtop or bottom fields; acquiring residual data from the UHD video data;and transmitting the broadcast signal, wherein the broadcast signalincludes the generated HD video data as a base layer stream and theresidual data of the UHD video data as an enhancement layer stream,wherein the broadcast signal further includes signaling information,wherein the signaling information includes a service type of a serviceprovided by the broadcast signal and a video format of the service, andwherein the video format indicates information representing whether thevideo type is 4K or 8K.
 2. The method according to claim 1, wherein thedown-sampled UHD video data of a first frame rate is converted intoprogressive HD video data of the first frame rate, and wherein theprogressive HD video data of the first frame rate is converted intointerlaced HD video data of the first frame rate.
 3. The methodaccording to claim 1, further comprising: generating the signalinginformation for signaling the base layer stream and the enhancementlayer stream; and multiplexing the base layer stream, the enhancementlayer stream and the signaling information.
 4. An apparatus fortransmitting a broadcast signal, the apparatus comprising: a firstencoder configured to generate high definition (HD) video data fromultra high definition (UHD) video data by converting the UHD video datato the HD video data, the first encoder including: a low pass filterconfigured to filter the UHD video data, a down-sampler configured todown-sample the filtered UHD video data using a sub-video samplingfactor which is a combination of even or odd pixels in a sampling unit,and a mode converter configured to generate, based on the down-sampledUHD video data, the HD video data in an interlaced way in which thegenerated HD video data includes interlaced HD video frames by scanningtop or bottom fields; a second encoder configured to acquire residualdata from the UHD video data; and a transmitter configured to transmitthe broadcast signal, wherein the broadcast signal includes thegenerated HD video data as a base layer stream and the residual data ofthe UHD video data as an enhancement layer stream, wherein the broadcastsignal further includes signaling information, wherein the signalinginformation includes a service type of a service provided by thebroadcast signal and a video format of the service, and wherein thevideo format indicates information representing whether the video typeis 4K or 8K.
 5. The apparatus according to claim 4, wherein the modeconverter is further configured to: convert the down-sampled UHD videodata of a first frame rate into progressive HD video data of the firstframe rate; and convert the progressive HD video data of the first framerate into interlaced HD video data of the first frame rate.
 6. Theapparatus according to claim 4, further comprising: a signaling unitconfigured to generate the signaling information for signaling the baselayer stream and the enhancement layer stream; and a multiplexerconfigured to multiplex the base layer stream, the enhancement layerstream and the signaling information.